Hydraulic systems, in particular hydraulic circulation systems are known for example in the form of heating installations and/or air-conditioning installations, in which a fluid heat transfer medium, for example water, is delivered in a circuit. The hydraulic systems for this, as a rule comprise at least one circulation pump assembly which circulates the fluid in the system.
It is also known, to be able to arrange switch devices such as valves for example, in such hydraulic systems. Switch-over valves which permit the switch-over between two hydraulic circuits or two heating circuits are often to be found in heating installations for example. Thus, for example in a heating installation, a heated heat transfer medium can either be delivered through a room heating circuit or a heat exchanger for heating service water, depending on the switch position of such a valve. The switch-over valves which are necessary for this as a rule are electrically driven and activated. This means that electrical drives with necessary electrical connections are required.